France, the UK, and the Organization for the Prohibition of Chemical Weapons have each declared that “sarin or a sarin-like substance” was used in the chemical attack on the town of Khan Sheikhoun in northwest Syria on April 4.

The French and British Foreign Ministers went farther and cited conclusive evidence that the Assad regime was responsible for the attack, by a Su-22 jet fighter firing a missile, which killed at least 93 people and wounded almost 600.

The OPCW, which is still seeking the co-operation of the regime to investigate inside Syria, did not attribute blame. However, it was clear that bio-medical samples from three victims during autopsies and seven in hospitals indicated exposure to a nerve agent.

Director-General Ahmet Üzümcü said, “While further details of the laboratory analyses will follow, the analytical results already obtained are incontrovertible.”

Sources from multiple governments — including Turkey, the US, Britain, and France — had already said that sarin was used and that the regime was the likely attacker. But no named official had gone on the record until Tuesday when Johnson told Parliament, “[There is] only one conclusion, that the Assad regime almost certainly gassed its own people in breach of international law and the rules of war.”

On Wednesday, Ayrault said, “We have elements that will allow us to show that the regime knowingly used chemical weapons. In a few days I will be able to bring you the proof.”

President Assad has insisted that there was no chemical attack at all, claiming that the evidence is “100% fabrication”.

Russia, Assad’s essential ally, has acknowledged that people died from chemical exposure; however, it has put out multiple, differing explanations. These include a rebel “false flag” attack to blame the regime, and a regime warplane hitting a rebel warehouse with chemical stocks.

None of the Russian claims has been supported with evidence, although they have been repeated — and extended — by conspiracy theorists, Assad regime supporters, and some Western journalists.

A “senior Israeli military officer”, briefing Israeli reporters, said on Wednesday that “a few tonnes of chemical weapons” remained in the hands of Assad’s forces, despite the regime supposedly handing over all stocks after its August 2013 attacks near Damascus that killed more than 1,400 people.

Some reports quoted the briefing officer as putting the amount at up to 3 tons.

Two days after the Khan Sheikhoun attack, Israeli Foreign Minister Avigdor Lieberman said he was “100% certain” that the attack was “directly ordered and planned by Assad”.

Opposition Town in Hama Province Gets Aid for 1st Time in 5 Years

The Red Crescent delivered 800 food baskets and 3,600 hygiene kits to the town, about 40 km (25 miles) southeast of Hama city. Throughout the area of southern Hama Province, cut off since late 2012, the aid delivery includes 3,600 food baskets, 10,000 blankets, 2,000 kitchen supply kits, three generators, and electric transformers and medical equipment.

Ahmad Karoum, president of Talaf’s local council, said the assistance was “not enough for families , as the population numbers about 3,500″.

US Officials: Regime Moves Warplanes to Russian Base

The warplanes were moved to the Hmeimim base at Basel al-Assad International Airport near Latakia. The re-deployment began soon after the US missile strikes on the Shayrat airbase in Homs Province, from which the Assad regime’s chemical attack on Khan Sheikhoun in northwest Syria was launched three days earlier, on April 7.

Local sources said up to 20 regime jets, some of them operational, were damaged or destroyed by the missiles, as well as hangars and support buildings. US Defense Secretary James Mattis claimed 20% of the regime’s operational warplanes were put out of action.

The positioning at Hmeimim means the regime’s aircraft are protected by advanced Russian-made anti-aircraft systems.

It is unclear how the regime air force will maintain bombing in areas such as the suburbs northeast of Damascus, where pro-Assad forces are trying to overrun remaining opposition territory, or in Daraa Province in southern Syria, where rebels have been advancing in Daraa city.

Russia has taken over much of the aerial attacks from the regime, according to local observers and videos of recent strikes.

Footage of a thermobaric, parachute-retarded bomb dropped by a Russian warplane on opposition territory in northern Hama Province:

Russia has stepped up its airstrikes in recent weeks — including incendiary, thermobaric, and cluster munitions — escalated further after the US missile attack on an Assad regime on April 7. The opposition said on Tuesday that the number and intensity of Russian strikes has now overtaken those by regime forces.

Russian airpower has been instrumental in pushing back a rebel offensive that took about 25 towns and villages in northern Hama last month. The attacks have also focused on destroying civilian infrastructure, including hospitals.

About The Author

Scott Lucas is Professor of International Politics at the University of Birmingham and editor-in-chief of EA WorldView. He is a specialist in US and British foreign policy and international relations, especially the Middle East and Iran. Formerly he worked as a journalist in the US, writing for newspapers including the Guardian and The Independent and was an essayist for The New Statesman before he founded EA WorldView in November 2008.